Carcinoma of the prostate with Cushing's syndrome. A case report with histochemical and chemical demonstration of immunoreactive corticotropin-releasing hormone in plasma and tumoral tissue.

A case is described of a patient with a small-cell prostatic carcinoma containing immunoreactive CRH, in conjunction with ACTH-dependent Cushing's syndrome. The serum concentrations of CRH, ACTH, beta-endorphin and calcitonin were all found to be above normal. Post-mortem examination revealed a prostatic tumour with multiple metastases, and a diffuse hyperplasia of pituitary corticotropic cells and adrenal cortical cells. In sections of the primary prostatic tumour, immunoreactive cells were demonstrable with antisera raised against human CRH, TSH, calcitonin and somatostatin, but not with antisera against ACTH or beta-endorphin. By radioimmunoassay the CRH-like material could also be demonstrated in extract of the prostatic tumour and the material from both plasma and tumour extract eluted at the position of human CRH on gel chromatography (Sephadex G-75). These findings provide support for the interpretation that the patient's Cushing's syndrome was due to a CRH-producing prostatic tumour. Finally, the origin and the clinical significance of the neuroendocrine cells in the prostatic carcinoma is discussed.